The present invention relates to a method and apparatus for manufacturing interconnected, easily separable, protective pouches, made from heat-sealable material, and adapted to enclose and protect objects.
To protect objects or parts which can be particularly susceptible to damage from abrasive contact with other parts or with shipping containers, the parts may be wrapped or enclosed in protective material prior to shipping. One technique is to use individual pouches, with wide openings, to enclose the parts. The pouches can be made by cutting various predetermined widths and lengths of material, assembling the material to form a pouch, and sewing the edges together. However, the cutting and sewing process to form such pouches is labor-intensive and the sewn seams can easily snag on the corners of the parts being covered, resulting in unraveled seams. In addition, because the pouches are supplied as individual units, packing of the pouches for shipment to the parts manufacturer can be labor-intensive, and the individual pouches can become tangled and unwieldy to manage during use.
There have been numerous attempts in the prior art to address the aforementioned problems. However, they have not been applied in toto to develop an efficient continuous process for producing pouches for large parts.
For example, U.S. Pat. No. 3,682,051, issued to Sengewald, and U.S. Pat. No. 4,500,307, issued to Bridgeman, teach that pouches can be made from a flat tube by perforating the tube across the tube, then heat-sealing across the tube. The resulting pouches are interconnected, have single seal lines across the width of the tube, and openings approximately equal to the width of the flat tube. The pouches can be separated by tearing at the perforations near the seal line. But, the size for the openings on the pouches are restricted to the width of the tube.
U.S. Pat. No. 3,552,278, issued to Guenther, teaches using prefolded material to manufacture pouches which leave an open edge along the length of the material and which are perforated between two separate and distinct heat seals. Guenther teaches that the two heat seals are made in a single step by using a sealer with parallel sealing edges. The resulting pouches are interconnected, have openings that can be varied in length, and can be separated by tearing at the perforations near the seal line. However, one cannot start with a single-ply sheet of material to make these pouches.
It is therefore a paramount object of the present invention to provide a cost efficient method for manufacturing interconnected pouches for parts, without cutting the material and forming stitched seams, starting with a single-ply sheet of material.